The long-term objective of this research is to improve breast cancer management by utilizing thermal information as an adjunct to mammography to aid in clinical decisions when confronted with equivocal mammograms. Before this objective is reached, the relationship of thermal abnormalities to breast cancer must be firmly established. This Phase II proposal is designed to obtain noninvasive thermal information using passive microwave radiometry in both breasts of approximately 1000 women scheduled to have needle localization procedures and breast biopsy. This noninvasive approach is a medically acceptable way to gain the necessary information from both breasts in each patient to permit left- to-right thermal comparisons between the cancer-affected and normal breasts. The strength of this Phase II proposal is that mammograms and biopsy-proven pathology will be available on each case. This will permit correlative studies between breast cancer thermogenicity with other factors, such as tumor histopathology, tumor size, grade and so on, in addition to angiogenesis determined on archival specimens. It may be possible to increase the yield of positive biopsies and reduce negative biopsies if women with equivocal mammograms and thermally abnormal lesions were biopsied, while women with equivocal mammograms and thermally normal lesions were deferred for biopsy pending further evidence indicating biopsy. PROPOSED COMMERCIAL APPLICATION: The long-term objective of this research is to improve breast cancer management by utilizing thermal information as an adjunct to mammography to aid in clinical decisions when confronted with equivocal mammograms. The data obtained from this study could lead to the development of improved detection techniques and equipment, based on noninvasive thermal sensing, as an adjunct to mammography.